1. Field of the Invention
This invention relates to an insulating refractory fiber linings having a hard outer layer or coating so that the insulating lining can be used in harsh environments without rapid deterioration of the hard, rigid layer material protecting the soft, resilient insulation material therebeneath.
More particularly, the present invention relates to an insulating lining which includes a mounting assembly for attachably engaging a surface to be lined, an ceramic fiber insulating layer, a mesh fixedly engaging the insulating layer and a hard face layer covering the mesh and anchored to the mesh by encapsulating or embedding a portion of the mesh, where the layer allows the lining to be use in harsh environments.
2. Brief Summary of Related Art
A number of United States patents have described insulators involving sinuously folded ceramic fiber blankets. U.S. Pat. No. 4,001,996 discloses a prefabricated insulating block formed of sinuously folded ceramic fiber blankets where the adjacent layers are needled together to intermingle the fibers in adjacent layers to form the block which then can be mounted on a surface.
U.S. Pat. No. 4,103,469 disclosed a modular fiber blanket furnace lining where the fiber blanket is sinuously layered to form a block structure and the hot surface includes a flexible cloth made from a continuous fiber of metal oxides to prevent erosion of the fiber making up the blanket due to high velocity furnace gases.
U.S. Pat. No. 4,123,886 disclosed a modular fiber blanket lining where the fiber blanket is sinuously layered to form a block structure and the hot face of the block is a high temperature ceramic fiber blanket or felt attached to the module by being sewn thereto.
U.S. Pat. No. 4,287,839 disclosed a lining including a plurality of insulating blocks of a insulating mat which is folded in a corrugated manner and possibly stitched in shape.
U.S. Pat. No. 4,339,902 disclosed a modular or block insulation composed of at least two layers of serpentine folded fibrous insulating blankets with the layers of the blankets being secured by means of extended folds of the hot face layers of blanket being interengaged with folds of the cold face blanket layers.
U.S. Pat. No. 4,595,358 disclosed an insulating material including a block with a sinuously layered ceramic fiber blanket having a thin sheet of stainless steel following the hot surface contour of the block and where folds of the sheet extend between adjacent layers of the blanket to form a tightly fit cover for storing heat and radiating the heat back to the heated product when thermal equilibrium is established.
Although insulating modular blocks of ceramic fibers for attachment to surfaces that are subjected to high temperatures are now well-known, these blocks generally are not successfully used in applications where the inherently soft fibrous hot face is subject to ablation by high velocity gases, erosion by abrasive particulate, deterioration due to fluxing or chemical attack. The relatively low emissivity of refractory fibers may be a detriment to efficient heat transfer in some applications. Fiber dust, unfiberized shot, or tramp fiber may also dislodge from the hot face and cause rejects in some applications. Efforts to use rigidizers or thin coatings to overcome these weaknesses have been generally unreliable because of insufficient strength of the adhesive bond directly to the fiber hot face. Thus, it would represent an advancement in the art to provide insulating linings which are capable of extended use in high temperature, highly abrasive and/or highly corrosive environments.